The goal of Dr. Gilkey's research is to specify the mechanisms underlying sound localization and masking. Understanding sound localization is an important step in the development of efficient 3-dimensional auditory displays and compelling virtual environments. The study of masking has important implications for basic auditory theory, for the specification and optimization of human performance in noisy environments, and for the problems of individuals with impaired hearing. These research projects include both free-field and headphone-based experiments on localization and masking, and modeling efforts examining neural networks and traditional signal processing models of audition.